Abstract
Purpose :
Tactile aids are a critical medium for spatial information for people who are visually impaired or blind. However, the lines, bumps, and physical textures traditionally used in tactile aids quickly becomes cluttered. Here, as an alternative to physical textures, we hypothesize that chemical coatings can deliver distinctive tactile textures in a card identification task with braille-literate blind participants.
Methods :
Playing cards were coated with one of two types of silanes: red cards were silanized with pentyltrichlorislane (C5) and black cards were silanized with n-butylaminopropyltriethoxysilane (C4-APTMS). Only numbered cards were used. After materials characterization, blind and braille literate participants (n = 10) performed a 2-alternative forced choice task (2-AFC) where two cards of the same number, one black and one red, are presented and the participant identifies which of the two cards is black by touch. This was repeated 10 times per participant. Prior to the task, participants undergo familiarization and training with feedback (see Figure 1a-b). Statistical analysis was performed with binomial distributions and confidence intervals determined by Wilson Score Intervals.
Results :
Participants, on average, could identify cards based on feel statistically significantly above chance (p < 1×10-5), with two of the five subjects correctly identifying 10/10 cards. (Figure 1c) Indeed, during testing, one participant was initially misidentified a card, then deliberated again, and then correctly sorted the card (no feedback is given during the 2-AFC task).
Conclusions :
We demonstrate that surface coatings can be used to identify objects. Future directions from an application standpoint is to use other materials that we have previously identified to distinguish between more categories, e.g., four different coatings that represent the four different card suits. From a basic science perspective, connecting our materials characterization data to the chemical structure may lead to the rational identification of future tactile coatings.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.